风电机组低电压穿越测试继电保护策略研究

为了提高电力系统的稳定性，电网要求风电机组具备低电压穿越能力。在测试风电机组低电压穿越能力时，为保证风电机组及电压跌落装置的安全，设计了一套包括反时限过流保护、电流速断保护、低/过压保护、低/过频保护以及差动保护等5个保护模块的继电保护系统，并在风电机组低电压穿越仿真测试平台上进行了验证。结果表明，所设计的继电保护系统可以保证系统故障时可靠动作，低电压穿越测试时不会误动作，能够躲过风电机组起动时的尖峰电流，起到保护电压跌落装置的作用。

Relay Protection Strategy Research on LVRT Test of Wind Turbines

In order to improve the stability of the power system, power grid requires wind turbines of low voltage ride through capability. To ensure the safety of wind turbines and voltage sag generator during the wind turbines LVRT test, a relay protection system with five relay protection models which includes inverse-time overcurrent protection, instantaneous overcurrent protection, low/over voltage protection, low/over frequency protection and differential protection is designed and verified on LVRT test platform of wind turbines. The results show that the relay protection system can guarantee reliable action in a system failure and no malfunction in low voltage ride through tests. The system can escape the starting peak current of wind turbines, thus protects the voltage sag generator.